II. Epidemiology
- Incidence: 1 in 40,000 births
- Most common etiology for short-limb syndrome
III. Pathophysiology
- Hereditary (Autosomal Dominant)
- Disease of cartilage and endochondral bone growth
IV. Signs
- Facial features
- Recessed Nasal Bridge
- Large brachiocephalic head (prominent forehead)
- Prominent jaw
- Trunk and spine features
- Normal trunk
- Dorsal kyphosis
- Backward-tilting Sacrum
- Slight Abdominal Distention
- Limb features
- Rhizomelic limb shortening
- Short muscular limbs
- Stubby hands with thick fingers
V. Associated conditions
- Eustachian Tube Dysfunction
- Sleep Apnea
- Hydrocephalus (infants)
- Lumbosacral spinal stenosis
VI. Radiology: Skeletal XRay
- Short bowed wide bones with expanded ends
- Increased bone density
- Characteristic cupping of Metaphases
- Incomplete glenoid fossa and acetabulum
- Wide joint spaces
VII. Course
- Adult height: 4 feet
- Normal intelligence development